Air-metering device



May 26, 1936.

y 1935-' F. H. RAGAN v &

I AIR METERING DEVIE Original Filed April 4, 1928 4 Sheets-Sheet 3 INVENTOR.

A TTORNEYS. I

May 26, 1936. F. H. RAGAN AIR METERING DEVICE 4 sheets-shee't' 4 Original Filed April 4, 1928 m na m www, z

'0//III/ Patented May 26, 1936 UNITED STATES Frederick u. Ragai; sharm negts, Ohio; ase` signorto W. R. Barhart, Jr., Cleveland, Ohioo, ,A

'Application April 4, 1928, Serial No. 267,;248`

Renewed October .2, 1935 I 17 Claims. (c. 221-435` The present invention relates, as indicated, to

air metering devices and more particularly to `that class of metering devices used for inflating vide an air metering device which will enable an inexperienced operator to adjust it to' secure,

any pressure desired. Another object is to pro- 40 vide 'a means of inflating pneumatic tires at a a rate much greater than that hithertc ordinarily attained. A further object is to provide a device positive in its action and not easily afiected by the accidental introduction of small particles of foreign matter, condensation of water vapor or other substances harmful to the operation of the ordinary device of this general nature; Another object is to provide an air meter-ing device which is of compact form, capable of being comgo pletely enclosed and lubricated. A still further object is to provide an air metering device which is inexpensive to manufacture, easy to assemble and install and of very moderate 'cost to main tain. An additional object is to provide a device' Theannexed drawings and the following de- V 35 scription set forth indetail' certain mechanism embodving the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention i may be used. e v

.4 In said annexed drawings:

Fig. l'iis a general view showing the external appearances of the device together with a diagrammatic representation of its connectionsto 45 supplying and receiving reservoirs; Fig. 2 is a device taken substantially on the line 3-3 of Fig. 50 2; Fig. 4 is a view similar to Fig. land showing a sligh't modification in the 'external appearance of the machine; Fig. 5 is a view similar to -Flg. 2

of a modified form of metering device, saidfig're 'being taken substantially along the line 5-5 of 55 Fig. 6; Fig. 6 is a transverse sectional view taken longitudina sectionai viewtaken upon a plane substantiay parallel to the plane of Fig. 1; Fig.` 3 is a partialitransverse sectional view of the.

substantially upon the' line 6--3 of Fig. 5; and Fig. 7 isa view of adetail.

' Referring more particularly to'themodiiication disclosed in Figs. 1 to 3, 'the reference numeral I indicates a post or other similar standard upon 5 which is mounted a housing 2 provided with an inlet pipe 3 and an outlet pipe 4 and enclosing a dial 5 with which cooperates a flnder 6. A pipe 1 connects the 'inlet pipe` 3`with a pressure t'ank 8 or 'with a pump (not shown) and'a fiexible tube 10 9 is connected to the outlet pipe 4 and c'arries at its free end the usual type service valve o which cooperates with the flller valvefli of the tire l2. The back plate |3 of the casing provides a mounting for ali of the Operating' parts of' the device. e y i In the upper portion of the casing, there 'is mounted a valve casing M provided with a bore i .munication'with the interior of the 'casing 14. said casing ll is further provided with-a bore l' for the accommodation of a` fltting 13 which is formed with 'one branch !3 to whichis connected a signal whistle 20, and with another branch 2l to which is connected one end of a tube 22, the' I function of which will be later described.

within the valve casing 14, a raised annular valve seat 23 surrounds a port 24 providing'communication between the casing and the fltting 30.

!8. This port 24' is adapted to be closed by 'a y valve comprising a valve e head 25 of resilient" material carried within a nut 25 which is' clamped i to one face of a flexibie diaphragm 21 by means of a screw 28 and washers 29 and 30 on opposite sides of' said diaphragm; 'The diaphragm isheld 'in place closing the open end'of the valve casing Il by means'of an annula'r ring '3l Secured to said 'casing by screws -32 or other equivalent fastening'means The screws 32 further secure to the valve casing M a bracket 33 housing a heavy compression spring 34, one end of which abuts againstthe washer 30, while the other end thereof abuts against a follower 35 which is adjustable through the agency of a screw 36 thread-` ed into 'the free end' of the bracket and locked *in adjusted position by a lock nut 31.

valve casing 33. The open end of the casing 38' projecting extension 4l which is formed with a bore 42 and is provided on its inner end with an annular valve seat 43 surrounding said bore 42 for engagement by a flexible valve 44. said valve 44 is retained in position at its periphery by means of an annular Washer 40 and a sleeve nut 40 screwed into the valve chamber. The bore 42 of the plug 40 is enlarged and' internally threaded at its 'outer end 'as at 41 for the accommodation of a connecting elbow 40 through which a pipe 49 is connected with said bore 42.

A stem 50 is slidably mounted in a suitable aperture in the casing in engagement with the valve 44 and projects outwardiy from the casing s. said stem so is threadedas t s intermediate its ends for the adjustable mounting ,of a pair of abutment members 52 and 53, and each of i said members is backed up by a lock nut 04. Each of said members 52 and 53 is provided with a shoulder 55, and s aid members are disposed with such shoulders facing each other. 4A` latch member SG'adapted to.cooperate with said abutment members, is mounted, through the medium of an, elongated slot 50 'in said'latch member, upon a ended expansion reservoir si mounted below and. to the left of the valve casing I4 as viewed in Fig. 2. The open endof the chamber 66 is closed by a 'flexiblediaphragm 01 secured thereto by an annular ring 08 attached to thejreservoir 00 by, screws 69 or other similar fastening means,

Through the medium of nuts 10 and washers 1| on opposite sides of-the diaphragm, a rod 12 is secured thereto in such a manner that flexure of n the diaphragm will reciprocate said rod. lr'tcita-` tion of the rod 12 is prevented by a pin 13 traversing a socket 14 into which the end of the rod 12 extends, and extending through a kerf 15- formed in said rod end. The closure cap 10 of a tubular casing 11 is likewisesecured to said rod whereby said casing 11 will be reciprocated when the diaphragm 01 is flexed. An extension 10 of the valve casing 30 provides a journal 19 for. a

rotatably mounted shaft 00 which carries at its outer end a crank handle 0l. i said shaft 00 extend into the open free end of .the tubular casing 11 and carries therein a screw for-med in its inner end with a cylindrical socket 03 for the reception of the reducedcylindricalfreeend 04 of the rod 12. A ball hearing unit .stis Secured between a shoulder on said screw' 82 and a disclike member 00, and said member 06 forms a guide and support for the free open endof the casing 11. V e x A tube 01is received upon said screw 02, and a pin 01' extends through the shaft 00, screw 02,

and tube 01 toinsure rotation of said screw 02 and tube 01 upon rotation of .the handle 0I. ,The tube 01 is formed, throughout a portion of its length, with an external left hand thread 00 and an internaliright hand thread 09. An intemally thrcaded collar 90 is adapted-.to cooperate with the external thread 00, and a pin ll is threaded into a socket provided in the periphery of said is closed by a plug 40 provided with an inwardly collar 90 and extends outwardly of the casing 11 through a slot 92 provided in said casing. whereby rotation of said collar 90 is prevented. A portion of the rod12 is polygonai in cross-section, as at 93, and a collar 94 having an aperture of 5 similar cross-section is slidably mounted on said portion and cooperates with the internal threads 09 of said tube 01. It will be readily apparent that the polygonal portion 90 or therod 12 will prevent rotation of the collar 94. "A heavy como pression spring 95 is mounted within the casing `11 surrounding the tube 01 and abuts at its one end against .the closure cap 19 and at its other end against the collar 90. A slightly lighter compression spring 90 is mounted within the tube 01 15 surrounding the rod 12,' and abuts at its one end against a' washer 91 adjustably backed by a sleeve nut 90, andat its other end against the collar 94. A collar 99 is mounted on the rod 12 in engagement with the closure cap 16, and is adapted 20 to engage the Washer, 91. v

A link !00 is swiveled on the pin 9| and is pivotally connected at`l0l, to the flnder 0, said flnde-being pivotedat !02 to a lug or boss !03 formed on the bottom of the housing 2. e

The casing 11 has integrally formed thereon or rigidly' attached thereto, a plate |04 which is v provided at a point slightly above said casing 11 with a screw-threaded aperture !05 for the reception of one end of a cylinder !06, said cylinder 30 being adjustable therein, and a lock nut |01 is V provided to lock the cylinder in adjusted position., The free end of the valve stem 50 is provided with a piston' head I 00 which is received in the cylinder IOG`, said stem extending slidably through 35 i a plug I 09 closing the adjacent end of the cylinder |06. A light compression spring l|0 is ,mounted between said plug I 09 and the inner e face of the' head !09. A slightly heavier comtance between said face and said plug.

The plate s'` provided with an upwardly *4 .projecting finger ||3 extending between the bifurcations 'll4 of a lever lis carried by, ashaft s adapted to operate the'whistle 20.

The casing 11 further 'carries a block ll1 whichmay be formed integraily therewith or 50 which may be attached rigidly thereto, andsaid block carries a pair of upwardly projecting cam 'members III and ll9 provided with oppositely a disposed cam faces I 20 and. I2I, respectively, for

cooperation withthepins 60 and 59, respectivelv 55 The operation of the above described device i is as"followsz i U Air under' pressure in thetank-a flows through thepipe 1 and inlet 3 into the valve casing I4,

overcoming the force of the spring 34 and fiexing 60 the diaphragm 21 to move the valve 25 away i from its seat' 23. Air may then flow through the port 24, fltting II, tube 22, and bore 39 into the valve casing'lt' Presuming thevalve 44 to be oif its seat, as shown in'Fig. 2, the air will thenc' .flow through 'bore 42, ntting 40, tube 49, and connection 05 into the expansion chamber 60 where it` will act upon'the diaphragm 01 to flex said diaphragm against the force of the spring 95 and move the casing 11 to the right as viewed in Fig. 7'0 i 2. The initial movement of said casing 11 com-` presses the spring 95 and moves the spring III into engagement with the pisten head, l00, at the same time bringing the forward'edge of the cam face !20 Just into enea-cement with the pin 7 SO, and simultaneously bringing the forward end of the collar 99 into engagement with the washer 91. Further movement of said casing' begins to compress, also, the springs 86 and I l I, and causes the pin Gli-to ride up along the cam face !20. This.

movement of the pin 60, of course, carries the point of the latch member 56 which is in engagement with the shoulder 55 of theabutment mem ber 53 slowly upwardly and, as the springs 95. 96, and ii i are still more compressed, the latch member 56 will finally release the abutment member 53. The compressed spring i li will then expand and force the valve stem 50 to the right asviewed in Fig. 2 to move the valve M into engagement with its seat 43, thus closing the bore 42 and preventing further flow of air to the chamber 86. During the movement of the latch member 56 caused by engagement of the cam"face |20 with the pin 80, the stem 50 is held against movement, and consequently the opposite end of the latch member cannot fall. As a result. the latch mem-' g ber is turned about the point of engagement of i the right hand end of said member with the abutment member 52, such movement being permitted by the elongation of the slot 58. Suchmovement, however, is in opposition to the force of the spring 62, and as soon as the valve stem'io has `been moved by the spring ili, the spring 62 snaps the right hand end of said latch'member 56 down into engagement with the shoulder, 55 of the abutment member 52. The above Operations put the device into condition for use.

If, now,- a motorist approaches the device for the purpose of inflating histires to the `desired pressure, he will rotate the handle si tomove the flnder 5 to such a position that it will indicate the desired pressure on the dial 5. Rotation of the handle si in a clockwise direction as viewed from the right of Fig. 2 will move the collar 90 sages, and. said passages r are' smaller than the" bore 69 or the bore through which the connection 65 communicates with the interior of the chamber 66. consequently, the air exhausts from the chamber 65 quite slowly, thus releasing the, pressure on the left hand face. of the diaphragm 81 until a predetermined value, dependent upon the' combined force of the springs 95 and 88 is reached. When the pressure in the chamber 66 assumes this predetermined value, the springs si and 96 will move the casing 11 toward the left until the washer 91 strikes 'the collar 98. thus taking the pressure of the spring 98 'off the collar 99. such movement of the casing 'I'l brings the cam face I2| just into contact with the pin 59, and slightly compresses the spring I lil. further movement of the casing 11 toward the left must be eifected by the force of the spring 95 alone, and consequently, the actual release of the latch 56 to per-mit opening of the valve is-dependent upon the setting of the collar 80 by the handle s Thus, when the pressure in the chamber &I

reaches the value determined by the setting of the nut 90, the spring 95 forcesthe diaphragm "I into further compressing the' spring i o and causing the pin 59 of the latch member 56 to ride upwardly.

along the cam face i2i `of the cam member e 5 to release the engagement of the latch 56 with the abutment member 52. Assoon as the abut- I gment member 52 is released, the force o! the spring o in combination with the'efi'ectof the pressure in'the valve casing 38 `on the valve 44 'o moves the valve stern 50 to the left. thus removing the valve from' its seat 43 and allowing 'the latch member to drop into, engagement 'with the a abutment member 53.' The movement of the cas-` ing TI also causes the flnger ||3 to swing the 15 lever l|5 to sound the whistle 20. As will be obvious, the opening of the valve M' will cause the pressure in the chamber 66 tobe built up once more, because of the restriction of valves n and ll and such'pressurewill move the casing 11 again to the right to close said valve M, i after which exhaustlon of the pressure in the res-' ervoir 66 will allow the casing 'IT to be movedback to the left to open the valve 44, and this alternate opening and closing of the valve 44 `w continue until such time as the pressure in the ti're l2 'or similar container has been raised to such a value that it will prevent exhaustion of the pressure in the chamber 38 to a value low enough to allow the casing 'IT to move to the end of its stroke to silenced only whenthe desired pressure has been attained in' the tire. f g

It will be apparent that. when the spring 9 5 is set for relatively low pressures, very little air would be admitted to 'the tire upon eachindlvidual opening of the valve u, and that, in the absence of some 'special provision, the speed of inflation would be very low. It is in'order to overcome this objection, that the spring 96 is provided. As is clearly shown in Fig. 2,- the force of spring 96 is increased as the force of spring 95 is decreased. Furthermore, it will be quite clear that the spring 96 plays no part in resisting the initial movement of the'casing TI to the right as viewedin Fig; 2 because of the clearance between the washer 91 and the collar-OO, but the spring 98 comes into 50 play to resist that portion of the'movement of the casing T'I which actually causes the latch 56 to release the stem 50 to ;permit the same to close' the valve 44. Conversely. while both springs 95 and 96 cooperate to etfect initial movement of the casing 'I'l toward the left, it is the spring 95 alone which causes that portion' of such movement which actually moves the latch 56 to release the stern to permit the opening of the valve".

Thus opening movement of the valve u is`con-` 00 trolled entirely by the spring while the closing movement thereof is dependent upon the combined pressures of the springs 85, 96, and ili. Thus the pressure in the'chamber'te required to. close the valve u remains a `constant ,forfany given machine, though it may be made to vary by any desired amount depending upon the relative load ratings of the springs and stand the relative leads of the integral and external threads u and sa, respectively, on the tube" 81.

It will be readily appreciated that a situation might arise in which the pressure in the reser Voir 0 would be too low toovercome the effect y g of the springs '96 and IC, and -yet wouldbe too m n to be communicatedto a Thus, in the absence of some provision, it might happen :that

a user would overinflate his tire because o! the Iailure oi' the device properly to operate. To

prevent such contingency, I have provided the safety valve 29, This valve is urged toward its.

seat by the spring 94, th'e force oi which may be varied by adjusting the screw 99. In use, the screw 99 is set in such position that the valve 29 will remain closed it the pressure in the reservoir 9 is 'not high enough to.ove`rcome the'cohbined force of the springs 99 and 99. Th's a predeternined minimum pressure must be exceeded in the reservoir before the valve 44 will open to permit thefcommunication of pressureto to the air metering device enclose'd ina .casins !22. A delivery pipe !29 extends outwardly from e said casing, and the flexible tube 9 is connected tosaid delivery pipe and carries at its free end the usual valve !II tor cooperation with the flller valve of a' tire !2, or the like. said casing`en-, closes a dia] 9 and a flnder 9. I

According to the present modification, the casing !22 includes a baclrplate !24 uponwhich is mounted a safety .valve casing !25 provided'with a bore !29 leading'` into the chamber !21 oi! said casing, said bore !29 being adapted to accommo date an elbow connection !29 to which is connected the inlet 'pipe 1. n j

The casing !25 is open at its ends and is externally threaded at one end as at !29 for the re- 'i ception of a cylindrical housinglll. said casing is internally threaded at its opposite end !or the reception of a plug !Il provided with a bored extension !92 proecting into said casing. A valve !39 comprising a leather, or other flexible disk, is clamped between an annular ring !94 andthe adjacent end o! said oasing !29 by means of. a sleeve nut !39 screwed into the housing .no. A stem! engagessaid valve !991 and extends longitudinally ot the' housing !99, said stem projecting e at its outer end through a suitable bore in an adjusting nut !31 screwed into'the outer end of the casing !39. A coiled spring !39 surrounds said stern !95 and has its one endbearing against a flange on the stem !36 while' its "opposite end bears against theadusting nut !91. As wiilbe e obvious, the compression ot the spring !99 may be p varied by adjustment of the nut !91. n

The plug I!! is suitably formed to receive one arm of elbow !99 to which is connected one end of a short pipe !40, the opposite end'oif which e posite end of the casing !42 is externally threaded for the reception oi' a cap !41 which, when screwed up tightly presses an annular' ring !49 tightly against the rimgportion ot'a valve member !49. said valve member comprises a disk of leather,

or otherflexiblc material, adaptedto seat upon said valve seat l49; and is providedwith a 'stem !99 extending outwa d y through said cap !41. The plug !49 is iormed to accommodate one branch of an elbow 49 to the other branch o! which is connected a pipe 49;

The stem !99 is threadedas at ll! in a region,

intermediate its ends for the reception of adjustable stop members !92 and !94, said member !92 being provided with a, shoulder !99, and .said

'member !94 being formed with a shoulder !99.

The latch 99 and the spring 92 are identical with the correspondingly numbered elements in the previously described modification. A roller !99 is mounted to underlie' the stem !99 in the region e o! said stops'to support the stem and prevent its sagging to move the' stop members !52 and !94 out of engagementwith the latch 99.

The expan'sion chamber of the present modir flcation comprises cooperating members !91 and !99 secured together to form a chamber !99.1

said members clamping between them a diaphragm !90. In the modification disclosed in nga. 1 to 3, it is necessary to disconnect the pipes 4 and 49 rrom the casing 99 in case the dia;-

' phragm rr must be replaced; These diaphragms do not stand up for'very along under use, and consequently' it is necessary to change them with some fr'equency. According to the present modincation. the member !91 is provided-with a port s which accommodates the connecting member !92 forconnecting the' pipe 49 to said port.

e A passage isformed rrom said co'nnecting'member !92 to said chamber !59 by said port IGI, an

aperture !93 in the diaphragm !90, and a passage !94 in the 'member' !99. .S imilar1y, communication is established ,betweensaid charnber !99 and the delivery pipe !29 through a passage !95 in e ment, it will be seen that the member !58 may be disconnected irom 'the member !51.' thus exposing the diaphragm !99 i'or removal and replacement,

tall without the necessityof disconnecting the pipes 49 and !23. A short stem or rod !99 is suitably connected tosaid diaphragm. for movement therewith,` and extends through a bore in a lug lfissecured to the member !51.

A tubular casing !10 is closed at one end by a member !1!' formed to provide ,a socket !12 tor the reception ot said lug !99. A shait !19 provided withlert hand threads !14 atlits inner end and with right hand threads !19 adiacent its outer end is joumalledinthefhousing !22 and in the cylindrlcal portion!" of a bracket !19 secured to the back plate !24.' A bushing !19 proi vides such journal. "me outer end !19 ot' the -cylindrical casing !10 is open. and snugly but slidably receives a flange !90 on said bushing !19, said flange ,providing a I ebearing for said end j!19 oi the caslng l1 fl.. 4 I I I An 'internally threaded collar I9! is received upon said shatt !13' in cooperation with the threads !14 andis provided with a laterally extending proje'ction !92 which passes through a slot !93 in the ot the casing !wand through a slot, !94 in a bracket !91, later to be described.

" A coiled'spring !94 abuts'at its one end against the closure !1! of said casing and-at its opposite with a peripheral flange!" which, in the position-ot the parts illustrated 'in Flg. 5, !s slightly ;end hearing against a seat member !99 slidably m mount'ed upon said shai't !19 and'backed by saidj bushing !19. said 'seat member !99 is i'ormed passes through'an elongated s lot !88 in ,the lower spaced from the end !18 oi the casingflll. The casing !18 carries adjacent one end, abracket !88 which maybe-formed integrally therewith,

or which may be rigidly attachedthereto, and said bracket has secured therein a cylinder !887 tor cooperation with a pisten head !88 onthe stern !50. The details of this cylinder and the pisten are identical with the cylinder andjpiston and cooperating parts disclosed in Flg. 2 and described in connection threwith. v

;From the base of the back plate 'Z'fifld substantially centrally of the length thereoi, there extends a curved bracket a tormedwith an up-` wardly projecting ear !82 `in which is mounted` apivot pin !88, the nder &being pivoted on said pin !88. The bracket e is ormed with an elongated slot !88` through which extends the lug !82 iormed on the collar !8! and a screw! !85 endoisaid flnder 8 and entersla suitable tapped --hole in said lug !82. It will be understood that this arrangement provides for the movemento! theiree end oi the flnder 8 over the dial i in eorrespondence to shifting of the .collar !8! along the shait !18.

A lug !81 extends inwardly from a wall of the housing !22, and a bolt !88 secures thereto one end ot-"a latch member !88, the other endotwsaid member being adapted tobe Secured to said back plate !28 by means oi: a second bolt 288.' The periphery of the flange-!88 oi' th'ecollar !88 is iormed with one or more notches 2!!! into anyone oflwhich the edge of the latch member !88 is adapted to enter when in the position shown in full lines in Fig. 5, wherebysaid collar is prevented n om rotation. The bolt '288 may be removed to permit the corresponding end ot the latch member I 89 to -drop down\ into the position shown in dotted Outline in Fig. 5 to permit adjustment oisaid collar !85 independently ot-the j collar !8 The housing m s. pso a'ea with ;in aperture closed by a transparent plate 282, said aperture registering with the dial plate 5 `.As will be readily understood,

ot the devlce herein described absorbs a certain amount of thepressureavailable 'in the reservoir 8. The pressure in such reserv'oirs often fall to a low value,- such as or e pounds. The tires of trucks run under a relatively heavy pressure, such as 75 to 85 pounds -and it has been found that such a pressure might'not be obtainable through the use of the present device i! the pressure in the reservoir were only 80 or pounds. In order to make it possible to deliver suchpressure to a heavy tire.I- provide a sleeve .288 prwsv fltted onto the flange 284 oi thenut !8! and extending a considerable distance toward the closure member !1! of thecasing !10. This sleeve is so dimensioned that; in case conditions as above outlined should arise, the driver may turn the i the reservoir 8 may be communicated to the tire without loss oi! pressure in the operation of the device. z

The operation of the modification disclosed in Figs. 4 to 7 is quite similar to'that of the modification disclosed in Figs. lto 3, but the iorner The valve !0 beingclosed, pressure will build' up said flgure; may take place before the' end 18 the operation Thus.

mechanism has certain advantages over the latter; 4 When the mechanism is flrstginstalled,- and the inlet; pipe 1 is connected to 'the pressure v reservoir 8, air=flows rrom saidreservoirthrou'gh the pipe 1 and conne'ction !28 to the valve cham- 5 through the bore .of the projection !82, the connection' !88. and the 'pipe !1.8 to ;the interiorof l the valve casing !42. Presuming thepartsxto be in the position indicated in Fig. 5.-theair will r flow thence through the bore" MG; connection l8,-

pipe w connecting member !82,'port !8!, aperture !88, and passage lfito the chamber' !58:

25 inthe chamber !88 until it attains "a value-suflii cient to act upon-the'diaphragm to compress 4 the spring' lsl. Asisobviousfroman inspection of Fig. -`5, a'certaln amount oi' movement ot- .the casing !18 toward the right. asviewed'in` of the casing !10 contactspwith. the flange !88 i on theseatmember'l88. r

This initial movement oflthecasing !18 toward the right brings the plug m of the cylin-.- 85

- r alongfthe cam face zoto release the 'engagejection IM.- This places theapparat'us in con- I dition ior usey v x 50 i when a motrist approachesthe deviceto inflate 'histires, he operates the handle 8! toro- `tate the shatt i18'in one direction 'or the other' to bring the end of the finden-8 opposite the de sired numeral on the'dial 8,it being understood 55 that such movement of the findet 8 iseflected by the longitudinal-'shiting'ot: the collar !8!, which results in'corresponding shiiting ot the lug !82. Such'rotation of the shatt !18 causes the coilars i !8! and '!88'to move in opposite directionsit e., oo

ii' the collar !8l moves to compress the spring !84,` the' collar !88 moves'to release :the compression of the spring !81: by acorresponding amount. Thus it will be seen: that, while the pressure required to"move the casinggnlin a 55 direction calculated td open'thevalve !48'may be varied 'by actuation oi the handle 8! the pressure value at which the casing !18 will move to efl'ect the closing of: thevalve !89 will not be varied by'such actuatiornr` i ;When the flnder 8 has been I motorist applies the valve l8'to`his tirevalve thus -permitting the air-:in thechamber !89 to flow out through .the pipe !28. Thisflowzreduces the pressure in-the;` !88,;since7`5 '70 properlysetthe .a "alone is sufficient to overcome'ih Th'i'svalue, of'

into engagement with thepin; Sam -on the latch member 56." Suchmovement ot the casing !10 brings the seat l member 188 into engag ement u with the bushing |`|8,athus relieving'` the casing I'IO'of the. pressure `of the'spriig m; Furthe" movement toward the. left F will -not 'take place',

thenu`ntil thepressure in the'chamber |59.falls to' a'value such ,thai-,the force'of the'sprlng !84 i course, is variable in accordance with the setting of the nut a. When-the pressure in the chamber !whats` fallen to the predetermined value," the springiu moves.` the' casing. l'loto-itsextreme "left-hand position,-thus' causing 'thelpin :59to"-'ride up along' the cam 'face' z to release: theengagement of 'the l'atch'sszwiththe shoulder l55`to permit 'the valve MS to open 'As has been explainedythe valveslo. and ll.

constrict `the passage through which the air;

- flows into the tire, and consequently the' opening cycle is repeatedsuntil the "pressure in the tire is so high as to maintain the pressure -inthe chainber !59 at a value too high to bezovercome :by the force ofthes'prin`g.i84:r-

. In caseit is' desired to 'vary the pressure in the chambervlfl at whichthe casing llois movedto the right, to c'ose-a vave m, theobolt zoo; can be. removed, the latch :199: swung to the ;position shown in dotted Outline 'in Fig.- 5, and thecollar..

! "adjusted independently ot the collar ,IBL Thereis apossibility'that the pressure in the supply 'reservoir 8 might drop to a value such; as to befinsufiicient to move the' casing .IN to the right to close the valve "9 and .yet to be` too high ?to be communicated directly, to the tire;

If' such a situation should' ariseythe tire would be infiated beyond the desirable "limit and' a blow-out might'result; 'It is for this reason that 4 `I have provided the valve |2`5 and its cooperati ing parts. The nut'l3'l is so set as' to-compress the spring !38 sufiiciently to preventtheopeningcf' the valve l33- when thepressure' in the reservoir 8 failsbelow' thepredeterminedvalue suflicient to move. theediaphragm I Sato cause closure of thevalv'e !49.

'Other modes of applying.. the 'p'rih' pe of my invention may be employed' instead of, the one'exi plained, change beingmade as regards themechanism herein disclosed, provided the means stated by any of the followingclaims orrthe equivalent of such stated means be employed' I thererore particularly point out and'distinctly .claimoas 'my invention:

1. An air metering device for supplying` compressed aii-to a. container inpulsations of, heavy pressurewithout danger of oversupply comprising a pressure source, aline adapted to connect said source with a. container, a valve insaid; line, and

-mechanism responsive to. pressure'in said l ne beyond 'said valve' for opening andclosing said valveto effect'pulsating delivery through said line, said mechanism 'comprising a fiexible'dia phragm having one faceexposedto the vpressure in said line, an element movablein one direction a by said diaphragm, a spring urging said element phragm havihg one face exposed to the -pre'ssure u i 4 thevalve |49`is closed'and the combined force of *the-.springs !84 'andlfl'l' moves the casing I'IO'" to theleftas viewed insFig; 5, thus1compressing the spring l losand bringing' the cam face l'2 I just in the opposite directionj-a second spring supple` menting thes action of -said'first-named spring after initial'movement of the first spring means" operable "bythe 'user of said device tor varying the compression r of said first-'named 5 j I 25 An air metering device forsupplying compressed air'to a contain'er in pulsations 'of heavy pressure without" danger" of' 'oversupply compris ing -`a' pressu'rejsourcga 'line' adapted to connect said sourcewitha container,`"a`valve^ in said line; and` mchnismrsponsive to "press'ure in said" line beyond said valve foropeningand closing said valve to eitect puls'atingdelivery through' said line, said me'ch'anism 'comprising a; flexible diaphragm having 'one' face exposed to"the`pressure in saidline, anielement movabl'e'inone direction by said'di'aphragm, a spring urging said element in the opposite' direction, a second' spring-having its one end engagi'ng a". sldable abut'ment, said ment but being'normally out'! contact there"-` with; and means operable by the user' of said device for varying difrerentially the 'compressionoi'both ofsaidspringsv 25 ;3:*An air 'metering device for supplying cox'nprssed air to a containerin`pu1s'ations'of heavy* pressure without danger of oversupply compris-" I ing a press'uresource; 'a line adapted to connect' saidsource with a container `a -vlvej in said eg so andmechanismreponsive to pressure in said linebeyond' said valve for opening alnd'closing' saidvalve to"ef fec't-"'pulsating delivery through said line, said mechanism comprising a flexible dia in said line, an element movablein one 'direction byjsaiddiaphragm, a spring urging said element in the opposite' direction, a second spring having its one 'end engaginga slidable abutment, said" abutment being disposed in the path of said ele ment' but being normally out of contact therewith, means operable by the user of 'said'device r for va'rying diflferentialiy the compression of both i ofsaidsprings, and means operable only by an authorized personior varying-the compression 45 of said second spring independently. .4. In an 'air metering'deviceg -the'combination with -a'source of air' under pressure and a resoervoir'congected thereto; of a. valvednterposed between aid source and said reservoir, a flexible" 50 diaphr'agni'in' said 'reservom `a casing` connected to said'diaphi'agm; a `spring' coaxially with' said casingand tending to' move the same-in' one' direction, and means' externally o: said casing tor causing said valve' to bej opened -uponjmovement 55 of said casin'g in'said'- one direction, and `tor causing said' valve 'to -`be closed" upon movement of'said casing-in the opposite direction. 5. ;Irlan air metering device, the=combination` with a sourceo! 'air'under pressure' and a reservoir connected thereto, ol a' valve' interposed between said source'and said' reservoir, a ilexible diaphragm in' said reservoir, a' casing connected to saiddiaphragm',-' `a compression spring in said casing and `having its one end'abutting against 65 and said reservoir and means actuated by the 75 '20 i c abutmentbeing disposed in thevpath of saidelei e a,o42,19o pressure in said reservoir for Operating said valve,

.whereby relatively high-pressures cause said valve to be closed while relatively low pressures cause whereby relatively high pressures cause said valve out varying the pressure value necessary to close said valve, and latch means for causing a lag and subsequent quick action in the operation of said valve.

4 8. In an air metering device, a pressure feed line, a reservoir, a valve between said feed line and said reservoir, means actuated by the pressure in said reservoir for Operating said valve, whereby relatively high pressures cause said valve to be closed while relatively low pressures cause said valve to be opened, said means including a differential spring means adjustable to vary the pressure value necessary to open said valve with out varying the pressure value necessary to close said valve, means to adjust said last-named meansand a member carried by said adjusting means to prevent closureof said valve.

9. In an air metering device, a pressure feed line, a reservoir, a valve between said feed line and'said reservoir, and means responsive to pressures in said reservoir for Operating said valve, said means including a pair of springs adapted to urge said means toward valve-opening position, and said springs being so arranged that only one eifects ultimate valve-opening movement of. said means while both oppose ultimate valve-closing movement of said means, and means to adjust the compression of said springs differentially. v

10. In an air metering device, a housing enclosing a pressure feed line, a reservoir, a valve between said feed line and said reservoir, a flexible diaphragm in said reservoir, a rod connected to said diaphragm, a shaft journalled in said housing in substantial alinement with said rod, a tubular casing having a closed end and an open end slidably receiving said shaft, said rod abutting against the closed end of said casing,gsaid shaft being formed with differential threads adjacent its opposite ends, a collar threaded on said shaft within said casing, a coiled spring having its one end abutting said collar and its opposite end abutting the closed end of said casing, a second collar threaded on the opposite end of said shaft, a second coiled spring having its one end abutting said second collar and its opposite end abutting a slidable seat, said seat being disposed in the path of. said casing but slightly spaced therefrom, means for preventing rotation of said collars, and means carried by said casing'for causing actuation of. said valve.

11. In an air metering device, a housing enclosing a pressure feed line, a reservoir, a valve between said feed line and said reservoir, a rod connected to said diaphragm, a shaft journalled in said housing in substantial alinement with said rod, a tubular casing having a closed end and 'an open end slidably receiving said shaft, said rod abutting against the closed end of said casing.

said shaft being formed with diirerential threads adjacent 'its opposite ends, a collarthreaded on said shaft within said casing acoiled spring hav-` ing its one end abutting saidcollar and its oppo-. site end abuttingtthe closed end fo'fjsaid casing, a 5 second collar. threaded ,onthe' opposlteend. of said shaft, a second coiled spring having its one end abutting said second collar and its opposite end abutting a slidableiseat, said seat being disposed in the path of said casing but slightly` spaced therefrom, means for preventing, rotatio'n 'of saidf collars, a graduated dial insaid housing', a flnderl pivoted in said housing, means connecting said first collar and said finder whereby movement of said collar moves said finder over said dial, and 15 means carried by saidcasing for causing actuation of said dial. e A

'12. An` air metering device for supplying compressed air to a container in pulsation of heavy pressure, comprising a passage adapted to be connected between a source of fluid under pressure and a' container, a valve in said passage, and

mechanism responsive to pressure in said passage plate being adapted' to positively hold said valve 30 in closed position, a member adapted to be moved by said pressure-responsive means to bias said valve toward closed position; and a spring engaging said member and'adapted to move the same against the tendency of said pressure-responsive 35 means to release said latch;

13. An air metering device for supplying compressed air to a container in pulsations of heavy pressure, comprising a passage adapted to be connected between a source of 'fluid under pressure 40 and a container, a valve in said passage, and mechanism responsive to pressure in said passage beyond said valve for opening and closing said va lve to efiect pulsating delivery through said passage, said mechanism including a latchmech- 45 anism comprising an oscillatable plate and spaced abutments on the stem of said valve,` pins en'said plate and cams adapted to' engage saidpins, said plate being adapted to positively hold said valve in closed position, a member adapted to -be' moved by 50 i ing in combination a snap valve, a pressure-responsive motor for opening and closing the valve, 6

and means for controlling the opening and closing ofnthe valve including a member Secured-to the motor, a pair of springs adapted to act in opposite directionson the member and means for conflning the springs so that only one'spring can 05 act on the member at a time. o

15. Apparatus of the class described comprising in combination a snap valve, a pressure-responsive motor for opening and closing the valve, and means for controlling the pressures atwhich the motor opens and closes the valve including a member securedto the motor, a pair of springs V i adapted to act in opposite directions on the mem- V ber, means 'for conflning the springs so that only v one spring can act on the member at a time, and 5 means !or adjustins the tension o! each spring independentiy of' the other spring.

' 16, 'Appar'atusotthe class desc ibeieomn rising in combnation a :map vaivem a presure-respons sive motor for opening and'cloing the valve, and means !or contr'olling the pressuteatwhieh the motor opens and `closes the valveinciuding a member Secured to the motor; a pah" of springsadapted to. act inobposite directions on the member, means ;orfconning'the springs so that onlyone spring can act on the member at a time. 'and 'means oradjusting thetension of 'each spring withoutaflecting the space relationbetween such spring and the member,

17. Apparatus o! the class described comprising in 'combination a snap .valve. a pressureesponsivemotor for openingand elosingfthe 'valve and means for controling the opening andlciosing o! the valye including' a member Secured to'` the moim-.a pair of springs adapted to' act in' opposite directions on the member and means for H. RAGAN. 

